This invention relates to improved cellulose nanocrystal fillers for rubber compositions and more specifically with the grafting of disulfide and thioesters onto cellulose nanocrystals for improved performance as a filler in rubber compositions. At least one embodiment describes a method to graft thiols or disulfides on CNC surfaces via esterification exemplified by 3-mercapto-propionic acid (MPA), 3-(acetylthio) propionic acid (APA), or dithiodipronanoic acid (DTDPA). The reaction may be carried out on CNCs highly dispersed in a suitable solvent and improved reaction conditions to achieve a favorable degree of substitution, DS. The embodiment further discloses how surface thiol groups can then be protected, in a second step, as thioesters or asymmetric disulfides to tune the hydrophobicity of CNCs to improve compatibility with styrene-butadiene, SBR, or natural rubbers.

Provided is a modified cellulose, a preparation method and application thereof. The modified cellulose includes a flame retardant cellulose ester film, and the preparation method includes: obtaining a homogeneous cellulose solution by adding a cellulose to an ionic liquid cosolvent system; obtaining a cellulose phosphite ester solution by adding dimethyl phosphite and a catalyst to the homogeneous cellulose solution for performing a transesterification; obtaining cellulose phosphite ester powder by regeneration solvent precipitation, washing, centrifugation, and drying of the cellulose phosphite ester solution; and obtaining the flame retardant cellulose ester film by evaporating solvent after dissolving the cellulose phosphite ester powder in dimethyl sulfoxide.

Provided is a modified cellulose, a preparation method and application thereof. The modified cellulose includes a flame retardant cellulose ester film, and the preparation method includes: obtaining a homogeneous cellulose solution by adding a cellulose to an ionic liquid cosolvent system; obtaining a cellulose phosphite ester solution by adding dimethyl phosphite and a catalyst to the homogeneous cellulose solution for performing a transesterification; obtaining cellulose phosphite ester powder by regeneration solvent precipitation, washing, centrifugation, and drying of the cellulose phosphite ester solution; and obtaining the flame retardant cellulose ester film by evaporating solvent after dissolving the cellulose phosphite ester powder in dimethyl sulfoxide.

It is an object of the present invention to provide fine fibrous cellulose capable of enhancing transparency and suppressing coloring, when the fine fibrous cellulose are processed into a dispersed solution or a sheet. The present invention relates to fine fibrous cellulose, in which the amount of substituents introduced is less than 0.5 mmol/g and the fiber width is 1 to 10 nm. Moreover, the present invention relates to a dispersed solution and a sheet, each of which comprises fine fibrous cellulose. Furthermore, the present invention relates to a method for producing fine fibrous cellulose, comprising: (A) removing at least a part of substituents from fine fibrous cellulose with a fiber width of 1000 nm or less having the substituents, and (B) performing a uniform dispersion treatment on the resulting fine fibrous cellulose after completion of the (A).

Provided is a method for preparing a flame retardant cellulose ester film, and the method includes: obtaining a homogeneous cellulose solution by adding a cellulose to an ionic liquid cosolvent system; obtaining a cellulose phosphite ester solution by adding dimethyl phosphite and a catalyst to the homogeneous cellulose solution for performing a transesterification; obtaining cellulose phosphite ester powder by regeneration solvent precipitation, washing, centrifugation, and drying of the cellulose phosphite ester solution; and obtaining the flame retardant cellulose ester film by evaporating solvent after dissolving the cellulose phosphite ester powder in dimethyl sulfoxide.

Provided is a method for preparing a flame retardant cellulose ester film, and the method includes: obtaining a homogeneous cellulose solution by adding a cellulose to an ionic liquid cosolvent system; obtaining a cellulose phosphite ester solution by adding dimethyl phosphite and a catalyst to the homogeneous cellulose solution for performing a transesterification; obtaining cellulose phosphite ester powder by regeneration solvent precipitation, washing, centrifugation, and drying of the cellulose phosphite ester solution; and obtaining the flame retardant cellulose ester film by evaporating solvent after dissolving the cellulose phosphite ester powder in dimethyl sulfoxide.

The invention relates to cellulose esters, the ester groups of which are at least partially containing phosphorus and are based on unsaturated carboxylic acids and reactive phosphorus components, wherein the latter are preferably phosphorus derivatives of sugar alcohols or of tartaric acid derivatives. The invention also relates to methods for preparing novel phosphorus-containing cellulose esters and to their use as flame retardants for plastics.

The invention relates to cellulose esters, the ester groups of which are at least partially containing phosphorus and are based on unsaturated carboxylic acids and reactive phosphorus components, wherein the latter are preferably phosphorus derivatives of sugar alcohols or of tartaric acid derivatives. The invention also relates to methods for preparing novel phosphorus-containing cellulose esters and to their use as flame retardants for plastics.